I don't know how else to explain it, but say you've got a relatively biggish candle (approximately 16cm tall and 6.5cm diameter). As it starts to burn down, it doesn't burn all the way out to the circumference. And as such, the wick gets sort of too short. Does that make sense? Anyhow, I'm wondering how on Earth to "fix" the candle so that I can still readily reach the wick and well, in a sense, keep the candle "useful."